Travelling to meet Martin Rees feels for me like travelling to meet a member of a mythical council of elders, or any such body of the wise that children imagine looks over and after the world. Rees, 80, who has been the Astronomer Royal since 1995, has the calm, open temperament of a man made to answer the fundamental questions of space, time and the universe.
We met at Trinity College, Cambridge, the academic home of Isaac Newton and 34 of Cambridge University’s 121 Nobel Prize winners. Trinity is the kind of college where Rees could, over a buffet lunch in the grand hall, casually identify a Fields Medallist among the fellows seated nearby. A portrait of Rees, who was master of the college from 2004 to 2012, hangs in Trinity’s Great Hall. Another, in the National Portrait Gallery in London, captures him best: gazing out of shot, with a Newtonian apple placed on the desk beside him, he appears amused, inquisitive and wry – as he is in person. But his views are disquieting.
“This century is a special one,” Rees believes, as it may be the one “where we as humans destroy ourselves”. That seems dire. “It is dire. We have a bumpy road through this century.” The risks, he thinks, are myriad, from our over-dependence on technology that could break down or be misused (“suppose the internet had failed during the pandemic”) to the exaggerated voice of extremists on social media: “It’s more durable than Trump. It’s an issue that’s going to coarsen our political discourse, and I don’t see quite how we’re going to get away from that.” The world is getting harder to govern.
It is also difficult to observe improvements in human nature over time, Rees thinks. “Although our lives are better than those of our Middle Ages and medieval forebears, the evidence for the lack of ethical progress is that the gap between the way the world is and the way it could be is wider now than it was then – and it will get wider still.”
Isn’t it depressing, I asked, that progress will always be an illusion? “It is depressing,” he replied, while sounding far from depressed. He seemed too buoyed by knowledge to be deflated by fact.
This century is not only the one in which we have an ever greater capacity to destroy ourselves; it is also the first in which we will be able to alter what it means to be human. Forty-five million centuries into the history of Earth, this is the one in which humans seem likely to “transition from flesh and blood towards electronic entities”, as Rees puts it. And we can, as he wrote in On The Future (2018), “have zero confidence that the dominant intelligences a few centuries hence” – whether transhuman or a form of artificial general intelligence – “will have any emotional resonance with us”.
The realisation that dawns on you, as you talk to Rees, is how primitive humanity is as a form of intelligent development. We will, as a species, be long forgotten in the cosmic future. “The future is at least as long as the past,” he said (so long as we avoid extinction). “We may not,” given the age of the sun, “even be at the halfway stage in the emergence of complexity. And when the sun dies, the entities watching that will be as different from us as we are from a bug.”
Rees appears to accept that all life must end, when many others do not. “Well we have to, don’t we?” he says with a smile. But some tech utopians dream of their intelligence being “uploaded to the cloud”, free of mortal bounds. How realistic is that proposition? “I think the question is, to what extent is it still going to be you? Because we are linked to our bodies and they could make multiple clones of this electronic thing, so which one is going to be you?”
Rees – who came up to Cambridge to study mathematics more than 60 years ago, having grown up as the only child of two teachers – still lives an active life: he comes into college and he writes books (his latest, If Science is To Save Us, is out this month). He lives nearby, in Cambridge, with his wife of 36 years, an anthropologist, and has long lived with a slightly curved spine that gives him a stoop but robs him of none of his zest – he served as president of the Royal Society from 2005 to 2010, while master of Trinity. “If we could go on as we are now,” he said of himself and those in good health, “I think we’d be very happy for a few hundred years.”
Yet time is passing. As a theoretical physicist, the notion of time is a subject of debate for Rees, but he does not doubt its constraints. “Some physicists argue that space and time are not the most fundamental things, and that they are constructed from something still more fundamental – so at that very deep level, you may say that time is not a fundamental quantity. But that’s like saying that a lump of sugar isn’t fundamental because we could break it down into atoms and crystals. That doesn’t make time, or the lump of sugar, any less real.”
The question of what to investigate is the central one for any scientist. As a younger man, as he studied the origins of the universe and the nature of black holes, Rees worked alongside the great physicists of our age, from Stephen Hawking to Roger Penrose. “We can now,” he said, “go back to the first microsecond of the universe with as much confidence as a geologist has in talking about the early history of the Earth.” But the first microsecond is critical. “Many of the key features of the universe – why it’s expanding, how big it is, why it contains atoms and radiation and dark matter – the answers lie in this first microsecond.”
Little is understood about that first microsecond. It is, Rees said, a question of “trying to guess what the physics might be like” as the conditions would have been “far more extreme than anything for which we have a foothold in experiment”. This uncertainty has left space for striking theories about that first moment, such as the idea there have been many big bangs, rather than just one. Yet “many features of reality”, Rees warned, “are going to remain a mystery, because our brains aren’t up to it”.
Rees worked in Albert Einstein’s wake as a cosmologist, but, unlike Einstein, he has diversified away from astrophysics in his later years. “Einstein realised that the obvious step” after postulating the theory of relativity “was to unify the forces of gravity with the other forces we knew about – electricity and magnetism, and the forces that hold atomic nuclei together – and he tried to do this. It’s what people are working on now, but in his time, it was certainly a hopeless quest, because not enough was known about the forces.”
Wary of a hopeless quest, Rees has instead increasingly turned his attention to the state of society. And it is our politics, rather than our inevitable end, that exasperates him. His new book explores the possibility of scientific advance saving society, but he knows that society cannot be saved from short-termist politicians.
Rees is particularly discouraged by recent Tory ministers, describing Boris Johnson’s government as “the worst” in his lifetime. “Conditions for the average person have got worse in the last 20 years,” he told me. Pay has fallen, work is more insecure, trade unions have long lost their strength. “We’ve gone in the wrong direction. It’s clear that the National Health Service is worse than it used to be. New Labour did many good things – Sure Start and [initiatives] of that kind, which the Tories then cut. I just feel the inequalities [today] are really grossly excessive.”
Martin Rees would like to see “an increase in social services and an increase in taxes on the wealthy” to pay for them. He describes himself as “Old Labour”. What does he mean by that? “In one sentence: to learn more from Scandinavia than from the US.”
This article appears in the 21 Sep 2022 issue of the New Statesman, Going for broke